Age-related changes of DNA winding and repair in human peripheral lymphocytes.

Superhelical density and incision capacity for UV light-induced damage have been studied in nuclear DNA of human peripheral lymphocytes as a function of donor age. With advancing age between 20 and 90 years the content of negative superhelical turns increases, whereas the ability to incise UV lesions is impaired. These data may be suggestive of an immature lymphoid cell state arising in aging.